Water circulation thermostat



Oct. 31, 1939. M. GAUL WATER CIRCULATION THERMOSTA'I' Filed Sept. 17, 1937 INVENTOR fl k 64w) A TTORNE Y Patented Get. 31, 1939 UNITED STATES PATENT OFFICE Max Gaul, Eppstein Taunus, Germany, assignor of fifty per cent to Max Goldschmidt, London,

England Application September 17, 1937, Serial No. 164,373 In Germany September 19, 1936 18 Claims.

The invention relates to a thermostat which serves especially on internal combustion engines for the automatic regulation of the varying flow of the cooling means from the engine block to the radiator or directly to the pump for the cooling means. In a previous case now Patent No. 647,117 issued in Germany, a multiple, high pitch thread is used, either alone or in combination with a single pitch thread, in order to make the movement of the disc or flap valve that is to be controlled a combined thrust and rotary movement. If both threads are used at the same time, there occurs a differential action in the positive or negative direction, which is related to the thrust movement. The present invention consists inv three further forms of construction of the original idea of the invention, in which the main characteristics, the rapid pitch thread alone or combined with a single pitch thread also provides an advantageous feature. An advantage of the invention, as compared with the previous device, resides in favorable and spacesaving adaptations of the thermostat to housings that are used under certain conditions of construction.

One objectof the invention therefore is to provide different adaptations of the thermostat using the rapid pitch thread.

Another object of the invention is to provide improved valves to improve the efficiency of operation and to reduce frictional resistance to valve movement.

Other objects of the invention will become apparent from the following description, the drawing, and from the claims.

The drawing illustrates the three forms of construction of the invention by means of a vertical plane and a plan view, partially in cross section.

Figures 1 and 2 relate to the first form of the invention;

Figs. 3 and 4 relate to the second form of construction; and

Figs. 5, 6, and 7 relate to the third form of construction.

The first form of construction (Figs. 1 and 2) shows a housing which consists of an upper part I and a lower part v2, which are screwed together in liquid tight relation. The upper part I terminates in a hose connection 3 for the connection of the line for the cooling means to the radiator, and the lower part 2 in a hose connection 4 for the connection of the line from the engine block. A hose connection added at the side of the lower part 2 of the housing serves as a connection to the so-called by-pass line, which leads directly to the cooling water pump.

The thermostat generally is mounted on a head platefi clamped between two packing rings 1 and 8 on the upper part I and the lower part 2 5 of the housing. The plate 6 has two sectorshaped openings 9, opposite to each other for the passage of the cooling means to the outlet connections 3. Openings 9 can be closed by a twowinged disc valve 10, rotatable on a centralbolt 10 I rigidly riveted to the plate 6 and this bolt has a multiple, high pitch thread, of which, however, in order to reduce friction, only two diametrically opposite working threads l2 need be provided. The valve disc Ill engages these threads by means of two threading projections l3, which can be made, for example, by a suitable bending or forming of the inner edge portion of the valve disc. This disc is connected rigidly by means of two arch-shaped side parts l4 and P5 with the 2 lower head of a thermostatic element l6, comprising substantially an axially elastic corrugated tube having a suitable liquid therein. On the upper cover surface of the element IS a blind hole nut I1 is fastened which is provided with a single pitch thread that may extend partially into the inside of the element. This nut turnably engages a correspondingly threaded lower reduced portion l8 of the bolt ll. One-of the side parts It performs the function of a rotary 3o slide valve with relation to the inner opening of the connection 5 lying in the lower part 2 of the housing, and in order that this may cause no friction between this slide valve and the surface on which it runs, the axis of the cylindrical surface of the slide valve I4 is eccentric to the axis of its path as shown by broken lines in Fig. 2. Also, it will be noted that the inner end of connection 5' is cut to substantially fit the outer surface of the eccentrically arranged valve l4 when the latter is swung to the right to closing position, from which it follows that sliding friction between the valve and end of the connection is avoided. It will be appreciated also that the shape of the inner end of connection 5 may also serve to limit the turning movement of the valve.

Below the critical temperature at which the thermometer is to begin to operate, the openings 9 in the plate 6 are held closed by the valve disc Ill, so that the cooling means, coming from the engine block, flows through the connection 4 and past the thermostatic element, out through the connection 5 and back to the cooling water pump. This control of the cooling means constitutes the so-called by-pass, which effects a rapid heating to the temperature favorable to the operation of the engine. If the temperature of the cooling means rises above the critical point, the thermostatic element expands and since its upper end is held on the threaded bolt I. as a substantially stationary point, the lower end moves downwardly and through the agency of the connecting lateral parts H and I5, the

valve disc I0 moves downwardly off the plate 6 a certain amount, corresponding to the expansion. However, on account of the multiple pitch thread connection between the valve disc in and the upper stationary part of bolt II, a rotary movement of the disc, parts i4 and I5 and element I5 occurs, so that, therefore, with the axial withdrawal of disc Hi, the openings 9 are also uncovered by the wings of the disc through a turning movement of 90. At the same time, the slide valve I slowly closes the opening of the connection 5.

By a suitable dimensioning and formation of the surface of the slide valve H, the closing of the mouth of the connection 5 can be effected more or less gradually or quickly. Moreover, the present form of construction of the invention permits an especially small construction of the housing in which the thermostat is mounted, and this is advantageous when the entire device cannot be built into the engine block or the radiator, but must be connected with the neighboring parts by pieces of hose. The position of these parts is generally such that the mutual arrangement of the three connections provided in the present form of construction is the most advantageous.

The second form of construction (Figs. 3 and 4) differs from the first to the extent that, in-

stead of a disc valve combined with a rotary slidevalve, two rotary slide valves are used. When the conditions of the construction permit, the housing is purposely given a different form, being made undivided from a single piece, and the connection 3 for the line to the radiator being arranged at the side and opposite the connection 5 for the so-called by-pass line to the cooling water pump. The connection 4 for the line from the engine block retains its position at the lower end of the housing. The top or cover of the housing in this case takes the place of plate 6 for fastening the bolt The chief difference between the second form of construction as compared with the first, consists in the use of a rotary valve with two control surfaces I9 and 20, so that both the line 3 to the radiator and the line 5 directly to the cooling water pump are controlled in the same manner. The axis of the slide valve is in this case also eccentric to the housing I, so that the placing of the control surfaces l9 and 20 on the openings of the connections 3 and 5 takes place without any previous friction. In obtaining this eccentricity of surfaces l9 and 20, the latter may be eccentric to the thermostat axis, with the latter offset with respect to the axis of the housing. The inner ends of connections 3 and 5 are shaped to fit the surfaces of the surfaces l9 and 20, respectively, when the parts turn from one position to another, and such ends also may serve as limits to the turning action.

The advantage of this form of construction of the invention consists in the fact that the slide valves l9 and 20 are not during the time the line 3 is open, subjected to direct flow pressure of the cooling means, which occasionally, for example, when in low speed may become very high due to the increase in speed of rotation of the pump.

Moreover, the spaced arrangement of the connections 3, l, and I lends itself to the adaptability of this form of construction.

In the third form of construction (Figs; 5 to 7) the housing with the connections 3, 4, and 5 have the same form as inthe previous form of construction. Also the bolt H is fastened in the top or cover of the housing I by riveting or the like. However, the slide valve, which here also is a rotary slide valve, instead of being provided with cylindrical control surfaces, has conical control surfaces 2| and 22, the direction of the inclination of the conical surfaces, corresponding to the purpose for which they are used, being opposed to each other. Moreover, the multiple, high pitch thread l2 on the bolt both at its upper and lower ends, terminates in axial portions 23 and 24 adapted to receive the threaded nut parts I3 (Fig.7).

With temperatures below the critical temperature, as shown in the drawing, the outlet at the connection 3 is closed by the control surface 2| of the rotary valve and the threaded nut parts |3 are in engagement with the upper axial thread portions 23. If the temperature rises above the critical point, where the thermostatic element l6 begins to expand, the slide valve 2|, 22, as a result of the position of the threaded nut part |3 in the thread portion 23 at first goes through a downward axial movement for a short distance, about one mm., which moves the control surface 2| downwardly and off the opening of the connection 3 (in Fig. 5 vertically downward). This immediately separates the control surface and the seat surface from each other and then the following rotary movement of the former with relation to the latter takes place without any friction. The rotation is caused by the passage of the threaded nut part |3 into the threads |2 of the bolt II, the outlet through the connection 3 then being gradually opened and the outlet through the connection 5 being closed in the same way. Also the advance of the control surface 22 in front of the inner opening of the connection 5 takes place without sliding friction, and

the space between the two may be very small. This space then is closed by an axial closing movement similar to the initial movement, as the threaded nut part l3 passes into the axial thread part. A reversed movement of the parts occurs when the thermostat contracts.

The advantage of this invention generally is similar to that of the second form of construction, but the friction is instead of being avoided by an eccentric mounting of the rotary slide valve, is avoided by the prescribed axial initial and closing movements, whereby certain advantages, especially structural, can be attained.

In general, in so far as arrangement of axes are concerned, it may be said that in Figs. 1 and 2, the axis of the valve coincides with the housing axis but that the axis of surface I! is offset with respect to the housing axis and moves about the latter in a path that substantially brings it and the axis of the curved inner edge of connection 5 into coinciding relation when the connection is closed. In Figs. 3 and 4, the axis of the valve is offset from the housing axis, and the axis of surfaces I9 and 20 are offset from the valve axis but travel in paths that cause them substantially to coincide respectively with the axis of the curved inner edges of connections 3 and 5 when in respective closing positions. The axis of either surface may coincide with the housing axis when in its closed position and the inner edges of the connections may be concentric to the housing axis. In Figs. 5 and 6, all surfaces and connection edges are concentric to the housing axis.

What is claimed is:

1. In combination, a housing having an opening the edges of which lie in a curved surface, a rotary valve having a curved valve surface, and means rotatably mounting the valve so that its axis of rotation is spaced from the axis of the first surface and also spaced from the axis of said valve surface.

2. In combination, a housing having an opening the edges of which lie in a curved surface, a rotary valve having a curved valve surface, and means rotatably mounting the valve so that its axis of rotation is spaced from the axis of the first surface and also spaced from the axis of said valve surface, the radius of curvature of said valve surface and the first surface being substantially the same and the axis of the latter substantially lying in the path of movement of the axis of the valve surface when the valve is turned and substantially coinciding therewith when the valve is in closed position.

3. In combination, a housing having an opening the edges of which lie in a curved surface, a rotary valve having a curved valve surface for opening and closing said opening, thermostatic means for turning the valve, and means rotatably mounting the valve in such manner with respect to the opening that the first surface is eccentric to the axis of rotation of said valve.

4. In combination, a housing having an opening the edges of which lie in a curved surface, a rotary valve having a curved valve surface for opening and closing said opening wherein the radius of curvature of said valve surface is substantially equal to the radius of curvature of the first surface, thermostatic means for turning the valve, and means rotatably mounting the valve so that said first surface is eccentric to the axis of valve rotation.

5. In combination, a housing having a pair of openings, a valve plate for closing each opening respectively, common means for rotatably supporting the plates in different and spaced positions, and thermostatic means for turning the latter means, and including a high pitch screw or thread connection to effect both rotary movement of the plates and also movement thereof axially of the screw, said openings and plates being so arranged that one opening is closed when the plates are turned in one direction and the other opening is closed when the plates are turned in the other direction.

6. In combination, a housing having a pair of openings, a valve plate for closing each opening respectively, common means for rotatably supporting the plates in different and spaced positions, and thermostatic means for turning the latter means, and including a high pitch screw or thread connection to effect both rotary movement of the plates and also movement thereof axially of the screw, said openings and plates being so arranged that one opening is closed by a combined rotary and thrust movement of one plate eifected by the high pitch screw.

7. In combination, a housing having an end wall having an opening and a side wall having an opening, a plate valve rotatably mounted on the end wall and adapted to close the opening therein, a curved valve member secured to the plate and adapted to close the side wall opening with the parts arranged that one opening will be closed when the other is open, and means including a thermostat for turning the plate and valve member together and simultaneously to move them in a direction normal to the end wall so that the plate approaches and seats on the end wall as it moves to closing position and leaves the plate when turning to open position.

8. In combination, a housing having an end wall having an opening and a side wall having an opening, a plate valve rotatably mounted on the end wall and adapted to close the opening therein, a curved valve member secured to the plate and adapted to close the side wallopening with the parts arranged that one opening will be closed when the other is open, and means including a thermostat for turning the plate and valve member together and simultaneously to move them in a direction normal to the end wall so that the plate approaches and seats on the end wall as it moves to closing position and leaves the plate when turning to open position, the surface of valve member and the edge of the side opening having curvatures eccentric to the rotary axis.

9. In combination, a housing having an end wall having an opening and a side wall having an opening, a plate valve rotatably mounted on the end wall and adapted to close the opening therein, a curved valve member secured to the plate and adapted to close the side wall opening with the parts arranged that one opening will be closed when the other is open, and means including a thermostat and multiple thread screw for turningthe plate and valve member together and simultaneously to move them in a direction normal to the end wall so that the plate approaches and seats on the end wall as it moves to closing position and leaves the plate when turning to open position.

10. In combination, a housing, an end wall and side wall and circumferentially spaced openings in its side wall, a valve member rotatably mounted on the end wall and having separated and curved valve surfaces adapted to close the openings respectively, the arrangement being such that one opening is clwed when the other is open, and means including a thermostat for turning the valve member, each valve surface and the edge of the opening it closes lying substantially in a curved surface eccentric to the rotary axis.

11. In combination, housing, an end wall and side wall and circumferentially spaced openings in its side wall, a valve member rotatably mounted on the end wall and having separated and curved valve surfaces adapted to close the openings respectively, the arrangement being such that one opening is closed when the other is open, and means including a thermostat for turning the valve member, each valve surface and the edge of the opening it closes lying substantially in a curved surface eccentric to the rotary axis, with one valve surface and the surface in which the edges of the opening it closes is located being of substantially equal radius.

12. In combination a housing, an end wall and side wall and circumferentially spaced openings in its side wall, a valve member rotatably mounted on the end wall and having separated and curved valve surfaces adapted to close the openings respectively, the arrangement being such that one opening is closed when the other is open, and means including a thermostat and a multiple thread screw for turning the valve member, each valve surface and the edge of the opening it closes lying substantially in a curved surface eccentric to the rotary axis.

13. In combination, a housing having an opening in its side,'a rotary valve member having a valve surface adapted to close said opening, said valve surface and the surface in which the edge of said opening is located when the valve is closed being inclined to the axis of rotation, and means for rotating the valve and also moving it axially so that the valve surface rotates to a position over said opening and also axially moves into in'- t clined surface engagement with the edge of the opening.

14. In combination, a housing having an opening in its side, a rotary valve member having a valve surface adapted to close said opening, said valve surface and the surface in which the edge of said opening is located when the valve is closed being inclined to the axis of rotation, and means for rotating the valve and also moving it axially so that the valve surface rotates to a position over saidopening and also axially moves into inclined surface engagement with the edge of the opening, said axial movement occurring before the valve turns from its closed position so that rotary friction is avoided.

15. In combination, a housing having circumferentially spaced openings in its side wall, a rotary valve member having circumferentially spaced valve surfaces adapted to close said openings respectively, one valve surface being in closing position to its opening when the other valve surface is in open position to its opening, said valve surfaces being inclined oppositely and to the axis of rotation and the surfaces in which the edges of the openings are located similarly being inclined oppositely and to the axis of rotation, means including a thermostat for rotating the valve in one direction to close one opening and open the other and to rotate the valve in the other direction to close said other opening and open the first, and including means for axially moving the valve surfaces in one direction prior to turning in one direction and to move them axially prior to turning in the other direction, whereby each valve surface rotates to a position over its opening and then moves axially into inclined engagement with the edge of the opening.

18. In combination, a housing having an opening the edges of which lie in a cylindrical surface, a rotary valve having a substantially like valve surface for opening and closing said opening, the rotary axis of the valve being displaced relative to the axis of said cylindrical surface, and means for turning the valve, the arrangement being such thatthe valve surface contacts the edges of said opening when the valve is turned to close the opening.

17. In combination, a housing having an opening, a high pitch screw element mounted on the housing, a valve turnably mounted on and operatively engaging the screw element and adapted to open and close the opening, and thermostatic means carried by the valve and expansible axially of the screw for moving it axially of the screw element, whereby the valve is turned.

18. In combination, a housing having an opening, a high pitch screw element mounted on the housing, a valve turnably mounted on and operatively engaging the screw element and adapted to open and close the opening, and thermostatic means carried by the valve and expansible axially of the screw for moving it axially of the screw element, whereby the valve is moved, said thermostatic means comprising a bellows expansible axially of the screw element and having one end connected to the valve and the other end turnably connected to the screw element.

MAX GAUL. 

